1. Field of the Invention
The present invention relates generally to the field of oral and nasal inhalers. More specifically, the present invention discloses a device for improving medication compliance by patients utilizing medication inhalers by providing visual, audible, and tactile indication of proper inhaler orientation, audible and tactile indication of proper inhaler shaking, and improved leverage and comfort during the process of depressing the oral metered dose medication vial.
2. Statement of the Problem
Inhalation has long been known as a method for administering medicines for distribution and absorption into the airways, lungs, and nasal passages. Inhalation devices are the predominant medication delivery system for treating asthma and other respiratory disorders such as chronic bronchitis. A variety of inhalation devices are commercially available for this purpose, and with each device liquid or powdered medication preparations are introduced by the patient into his or her respiratory system where the medications are finely distributed throughout either the bronchial airways and alveoli or nasal sinus cavities.
Hand-held metered dose inhalers are the preferred method of treatment for most common respiratory ailments, allowing the patient to inhale medication when needed. It has been reported that a large majority of patients using inhalers do so incorrectly. Creer et al., "Medication Compliance and Asthma: Overlooking the Trees Because of the Forest," Journal of Asthma, 33(4) 203-211(1996), Hampson et al., "Reduction in Patient Timing Errors Using a Breath-Activated Metered Dose Inhaler," Chest 106: 462 (1994)!. It is commonly appreciated in the medical profession that many patients do not obtain the full benefit of inhaled medications because their inhalation technique is incorrect. Indeed, getting patients to correctly use inhalers is a major problem, especially with patients who use their inhaler infrequently. In general, it is necessary for a person utilizing an oral inhaler to properly align the mouthpiece with their mouth and throat and inhale properly and deeply while dispensing the medicament. With a nasal inhaler it is important to align the inhaler and nose to direct the spray towards the back of the nose into the nasal cavity. Although simple in description, the operation of both oral and nasal inhalers is more often mis-practiced with the unfortunate consequence that some patients may stop taking their medications because they are not seeing any appreciable benefit. Additionally many patients, having failed to obtain expected benefits through prescribed usage, will overuse the inhaler, subjecting themselves to increased risks of side effects caused by a higher than normal dose, such as fungal infections of the mouth and throat with inhaled steroids as well as nervous system over stimulation due to excessive dosing with beta agonists (e.g. albuterol).
Proper use of an oral inhaler requires seven recommended steps of (1) correct assembly of the parts, (2) shaking of the inhaler before use, (3) slow exhalation of tidal volume, (4) correct positioning of the inhaler at the mouth or nose, (5) activation immediately after initiation of inhalation, (6) slow, deep inhalation, and (7) breath holding for 6 to 10 seconds. In one reported study, Amirav et al., "What do Pediatricians in Training Know About the Correct Use of Inhalers and Spacer Devises?" J. Allergy Clin. Immunol. 94: 669 (1994), pediatric residents were asked to demonstrate the correct use of inhalers as if they were instructing patients. The most common errors included not shaking the inhaler (only 18% of the residents did it correctly) and insufficient breath holding (28% of the residents did it correctly). In November, 1996 (American College, Allergy, Poster Session) a study by Wanderer et al., inhaler technique was observed in 67 asthmatic patients who had not been seen in private allergy practice for at least one year. The most common errors included not shaking the device before use (40%), improper positioning of the inhaler vertically (45%), coordination problems (31%), and insufficient breath holding (25%). Together these studies underscore the need for developing methods and engineering controls to improve correct inhaler technique.
Of the problems reported, two of the most significant are not shaking the inhaler prior to use and improper vertical orientation. Since the active medication and aerosol propellant are frequently in suspension within the vial, it is necessary to shake the mixture prior to use. Shaking is necessary to insure that settling of the aerosol components does not result in an improper dose of the active medication. This is particularly true in cases where the inhaler is not used for days at a time. The second factor of concern is proper vertical orientation of the inhaler and the patients head. As with most propellant systems, if the inhaler is not properly oriented when activated the user may dispense an improper mix of propellant and active medication, resulting in improper dosing. Further, during inhalation, improper orientation of the inhaler may also result in impaction of the medication to the tongue, roof of the mouth, side of the mouth, sides of the nose, or throat. Improper orientation of the user's head in relation to the orientation of the inhaler is also problematic. When a person's head is tilted forward, human physiology is such that the airway to and from the lungs becomes more constricted, significantly restricting the flow of air to and from the lungs. Restricting the air flow is not desirable with the use of oral inhalers as it reduces distribution of the dose of medication throughout the bronchial passageways.
In addition, some types of inhalers will not function properly unless the inhaler is held in a substantially vertical orientation. For example, the Maxair Autohaler includes a valve mechanism that only releases medication when the patient exerts an adequate inhalation effort to ensure that the medication will be inhaled into the lungs. However, this valve mechanism is sensitive to orientation, and will not function unless held in a substantially vertical orientation.
Improper orientation during use may be attributed primarily to several factors. First, patients may not be aware or not recall the proper orientation of the inhaler. Second, it is difficult to judge the orientation of an inhaler located directly in front of the person's nose. In addition, some patients experience difficulty depressing the aerosol vial, especially patients with weak hands such as with arthritis or other disabilities. To date, the traditional approach for improving inhaler technique has involved the implementation of educational programs to teach health care workers and patients about the proper use of inhalers. This approach is time consuming and requires expensive human resources. Moreover, some patients use their inhalers sporadically with long intervals between use. Lack of practice and memory recall contribute to improper use of inhalers such that patients need to be reinforced periodically on the proper use of these devices. To aid in reinforcing and teaching technique, several inhalation devices have been developed to help insure proper use and provide feedback, including the following:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Fowler 3,404,681 October 8, 1968 Kistler 4,291,688 September 29, 1981 Wass et al. 5,349,945 September 27, 1994 Del Bon et al. 5,355,873 October 18, 1994 Mishelevich 5,363,842 November 15, 1994 ______________________________________
Fowler discloses a general example of an oral inhaler aerosol dispenser device for administering a medication by inhalation. To aid in encouraging the inhaler user to inhale during administration of a measured dosage, air passage through the inhaler's housing is only possible after the aerosol container has been depressed. Following placement of the inhaler within the mouth, the user inhales and produces a partial vacuum. Depressing the aerosol container dispenses a metered amount of medication and at the same time allows air to flow through a gap created between the delivery tube and the aerosol container into the mouthpiece.
Kistler discloses an oral inhalation device of the type adapted to receive and locate an aerosol container designed to administer a multiplicity of metered doses. To aid in achieving proper inhalation during dose administration, the inhaler device contains an audible signal generating means in the air passageway within the inhaler hosing. When the patient properly inhales through the inhaler, a confirming whistle sound is produced. Failure to inhale at a sufficient rate, or exhalation, will not produce the confirming whistle.
Wass et al. discloses an oral inhaler of the aerosol dispenser type for use with an aerosol vial. Within the dispenser is located an indicator assembly that reports the number of doses dispensed or remaining in the aerosol vial.
Del Bon et al. discloses an oral inhalation device for use with an aerosol vial in which the air flow through the inhaler may be variably restricted. To insure against accidental firing of the aerosol vial in the inhaler, as well as proper inhalation by the using patient, a positive locking unit is employed. Placing the mouthpiece of the device within the mouth, the using patient begins to inhale. The flow rate of air through the inhaler may be adjusted to accommodate patients of different age and lung capacity. The reduced air flow through the inhaler results in a suction that disengages the locking mechanism, allowing the aerosol vial to be depressed, thus dispensing the medication.
Mishelevich discloses an oral inhaler device for use with an aerosol vial. This inhaler device detects, reports, and records information regarding its use, such as how much air is inhaled through the inhaler housing during use, the time involved for inhalation, and when in this time course the aerosol vial was depressed. This device uses a microprocessor to compare actual time to target time as well as recording the history of usage for later report to a healthcare professional. Immediate response of the dosage administered, air inhalation and other information are also provided to the user on an LCD display.
3. Solution to the Problem
None of the above prior art references show a device that provides immediate, easy to see, visual as well as audible and tactile indication of proper inhaler orientation during use. Additionally none of the prior art references provide the inhaler user with an audible and tactile confirmation of proper inhaler shaking prior to use. Further none of the prior art references address the difficulty experienced by some patients in effectively depressing the aerosol vial. The present invention overcomes these shortcomings associated with the prior art systems. With the mouthpiece positioned at or within the mouth, or the spray tip within the nostril, the user must properly position their head and the inhaler in the correct vertical orientation. Correct orientation will cause an indicator ball to become visible to the user. The user with impaired vision or under dim light conditions will know how to hold the inhaler in the correct position based on tactile and auditory feedback of the ball moving to the front of the tube in the cap. Shaking the inhaler prior to use causes the indicator ball to rattle, thereby serving as a audible reminder. In addition, the user can feel the vibration of the ball ratting inside the inhaler which also serves as a reminder to shake the inhaler. The preferred embodiment of the present invention when applied to oral inhalers includes an ergonomic cap having a top surface curved to fit the contour of the first finger knuckle. The ergonomic shape of the cap reduces the force required to depress the aerosol vial, and makes the inhaler easier to use. When applied to nasal inhalers, the preferred embodiment of the present invention includes an orientation guide preventing the nasal pump from rotating out of alignment with the visual indicator.